The most common example of mobile communication devices are cellular telephones. These devices are in common usage in most metropolitan regions of the world. Their prevalence has resulted in certain expectations people have about the aesthetics of such devices, and manufacturers design new mobile communication devices with such expectations in mind In addition, these expectations and design conventions of cellular telephones influence the design of other mobile communication devices, such as hand-held two way radios used by, for example, public safety and law enforcement personnel.
One aspect of mobile communication device design that has become common is the lack of an external antenna. Early cellular telephone antennas were entirely external screw-in type elements that resembled antennas used (and still in use) on two-way radio devices. However, cellular communication has since migrated to higher frequency bands, which has allowed the physical size of antennas for cellular telephone devices to be reduced. Over the years manufacturers have found various antenna geometries and configurations that have allowed for antenna designs that are entirely hidden such that cellular telephone devices using them appear to have no external antenna element. Two-way radio devices, however, which typically operate in significantly lower frequency bands than cellular telephone devices, have not been able to follow the trend of reducing the antenna size due to the wavelength and the required physical size of a radiating element necessary for acceptable radio performance.
Accordingly, there is a need for an antenna structure for a communication device that allows for an apparent substantial reduction in the size of the antenna without sacrificing radio performance.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.